Control force

jm-urbani

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Joined
Dec 21, 2010
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French Riviera
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home built mono seat
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In case it may be of some help, in this book:


there's a description of the control forces of an MTO gyro, stick forces included. Pages 105 ... 161 Yes, it is in German, sorry... To my knowledge, this interesting book hasn't been translated yet...
I have carefully read this document in which they don't say anything about the effect of the blades twisting effect on control forces .

on the other hand the formulas in this document are interesting

thx
 

Doug Riley

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Jan 11, 2004
Messages
6,403
Chuck, an odd tidbit on this topic is in the old NACA report about the testing of a 40-foot Pitcairn gyro rotor in the full-size Langley wind tunnel. The authors claim that the rotor blades were built with an aft CG. They state that this produced a sort of constant-speed effect. As long as the blades were loaded and hence coning, a random increase in RRPM would create additional centrifugal effect acting at the blades' CGs. This, they say, would pull the trailing out-and-down, thereby cranking in more twist. It seems that RRPM might still "run away", though, if you flew such a rotor fast enough.
 

C. Beaty

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Apr 16, 2004
Messages
9,909
Location
Florida
A tail heavy rotorblade isn’t all that different from a tail heavy airplane; both are unstable vs angle of attack.
Skywheels rotorblades provide a perfect illustration of this; pitch the wrong way in response to gusts and on heavy machines are apt to randomly pitch nose up and do a tail stand.
This characteristic is frequently misinterpreted as high lift or in case of the extended float on landing; high inertia.
 
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